As far as closets for boats, caravans and the like are concerned, many problems must be faced. Such closets must be easily installed, stable and odourfree and it must be possible to empty such closets without risk of congestion in valves and conduits.
As far as trailer toilets are concerned, discharge is possible only at suitable collecting places, whereas boat toilets possibly may be discharged directly into the lake. This means that the emptying system of a boat toilet may be slightly more complicated than such a system for caravan toilets; it will be obvious, however, to an expert on the field, that only small alterations of a boat closet system will be required to adapt the system for use in larger vessels, such as floating houses. Accordingly, the following description will refer to a boat closet and the problems solved by the present invention in connection therewith.
Boat closets both with and without a collecting tank are well-known. In respect to rules expected to be issued regarding boat toilets, such rules presumably forbidding direct discharge into the lake, the sewage collecting tank will become a necessary part of the system. By the way, certain countries already forbid direct discharge of closet sewage into lakes.
Boat closets with discharge only into the lake for obvious reasons cannot be used in habours, beach bays and small waters. Because the majority of spare-time boats is used in "close-distance waters" of this type the closet in practice will never be usable.
In order that toilets of this type may be used to a greater extent they may be provided with sewage tanks. Such tanks, however, can only be discharged directly into the lake which means that closets having this type of tanks substantially has the same limited range of use as closets without a tank. However, there are certain portable tanks intended to be emptied ashore and requiring transport between the boat and the emptying place. Apart from the inconvenience caused by this procedure, the capacity will be limited to a great extent.
There are also closets adopted for discharged directly into the lake or ashore, a tank being provided for collecting the sewage between dumpings. In these closets the tank can be released for direct dumping into the lake after each use of the toilet. These known closet systems comprise complicated tubing and valves of a type subject to obstruction and malfunction.
A still more complicated system is the recycling system using a specific flushing liquid, normally some type of oil mixed with deodorants and bactericides such as formalin. While this flushing liquid is circulated in the system, the sewage is separated into a collecting container. However, it is difficult to achieve a simple and efficient separation and to avoid unpleasant odour emanating from the circulating flushing liquid. In systems without circulation it is a general problem to keep the flushing water consumption at a minimum. Another problem resides in the lack of available closet systems suitable for most boats and caravans, which means that closet arrangements must be specifically ordered for each type of use.
It is the purpose of the present invention to eliminate or at least minimize the above-explained draw-backs. This purpose is achieved by means of a closet of the type indicated in the claims which also state the specific characteristic features of the invention.